This invention relates to a liquid crystal display device comprising a row and column array of liquid crystal display elements defined between two plates which respectively carry sets of row and column address conductors, and a light shielding matrix of electrically conductive material in the form of a grid having portions extending between the display elements which is carried on one of the plates and electrically insulated from the set of address conductors on that plate.
Liquid crystal display devices can employ a matrix of light shielding material to improve display quality. Such a matrix is commonly referred to as a black matrix and consists of a light blocking layer which is patterned in a grid form having strip portions, i.e. sections, which border the display elements and usually slightly overlap the display elements around their edges. The grid prevents un-modulated light from between the display elements degrading the display performance, thereby improving contrast. A metal is preferable as the material of the matrix layer since it reflects rather than absorbs light energy and can be provided as a comparatively thin film.
Liquid crystal display devices of the kind having sets of row and column address conductors carried on separate plates can be of the passive variety in which the display elements are formed simply at the cross-overs between the row and column conductors or of the active matrix variety in which one plate carries a row and column array of display element electrodes which are connected to respective address conductors on that plate, usually the row address conductors to which scanning signals are applied, via two terminal non-linear devices such as diodes or MIMs. The other plate carries the matrix of light shielding material together with the other set of address conductors, i.e. the column address conductors to which data signals are applied, each of which extends over an associated column of display element electrodes.
A problem commonly experienced in such liquid crystal display devices which can significantly impair their performance, particular in larger area displays, is that of cross-talk. Cross-talk can occur both horizontally and vertically within the display picture.
Especially horizontal cross-talk can be a serious problem and has been found to be difficult to remove. This is particularly the case with display devices which use a metal black matrix.